Distance control of soft robot using proximity sensor for beating heart surgery

摘要

This paper presents the integration of a soft robot with optical fiber based proximity sensor which is designed for beating heart tracking in minimally invasive surgery (MIS). This cable-driven soft robot, made of silicone rubber, is low cost, lightweight, sterilizable and compatible for magnetic resonance (MR) environment. During non-contact and contact situation of robot manipulation, there is a phase where sensory information (force or image) is missing. Our proximity sensor system is designed to solve this problem. The proximity sensor, a 4-point sensor array, uses 4 pairs of emitter and receiver optical fibers to measure the light intensity of surrounding environment. The 4-point sensor array is mounted on the 10 mm diameter soft robot tip, with channels inside its body where cameras and surgical instruments could be integrated into. It is the first time using proximity sensor to control the motion of soft robot in beating heart surgery for the tracking task. A distance calibration model is built before the tracking experiment. Employing a position control method with gravity compensation, experiment is conducted and test results have shown the validity of our controller and system.